<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    // 九行九个
    var str = ''

    for(var j = 1; j <= 9; j++) {

      for(var i = 1; i <= j; i++) {
        //   t  tab  四个空格
        str += i + '*' + j + '=' + i * j + '\t'
      }

      // n newline 新的一行
      str += '\n'

    }

    console.log(str)
  </script>
</body>
</html>